BTW: is it adsense you are setting up? Did you put the adsense (or any text) in the GAB_custom_adsense template? Did you set up the ads in the scripts correctly?
The ads are defined in the script (generally MASTER while all others 'use master' unless you want to override the setting). For adsense, you need to have an ad block in the script in question, the wrapper template needs to be set to standard and the custom/adsense put in the ad pull down box
Also, all have to be marked as 'active'